source of info for roof construction

[browfish]

Hi
I am currently in the process of building a huge extension doubling the size of my semi (sorry, just realised how that sounds). Anyway, i have a builder who has put up the brick work and a chippy who is currently cutting the roof timbers. I have a single storey section that is 6x4m with a single ridge and gable end, and a a double storey section which is more complex.
When the roof timbers have been cut, it is back over to me to carry on so I am after information on the construction of the roof from there on. Any idea where i can find this, or can anyone give me a few pointers?
I am imagining its a case of felting, battoning and tiling but can anyone expand?
thanks
james

 

[browfish]

no ideas?

I have the A frames up all the way along and i just want to know what the next stage is? Cant find anywhere on the net on how to construct a roof

 

[Freddie]

no ideas?

I have the A frames up all the way along and i just want to know what the next stage is? Cant find anywhere on the net on how to construct a roof

First of all your roofer must brace the roof timbers by putting diaganals across them and nailing every rafter--both sides of the roof to stop the whole lot coming down.

Then you get your felt and roll it out across your rafters with approx 3" hanging over the bottom where your gutter will be, and nail it when you have it square and tight at the top of the felt on every rafter to keep it in place and taught.

Then get your battens or laths cut them to size of the roof, if they arent big enough cut them so they can be joined on a rafter and stager the joints as much away from each other as possible--only cut 4 per time just incase of discrepancies.

Then work out your fist batten mark on the rafter allowing for correct overhang of tile or slaste and mark your felt at both ends and then use a chalk line to mark the lot--treble check your measurements and then nail your first batten lenth across--go back and re-check and eye it up and then do your second allowing for correct overhang of tile slate.

When you get to where you needsecond layer of felt over lap to the marks and nail felt at top again and then carry on nailing battens on double checking your line marks and measurements all the time.

On the very bottom batten which should be level with the end of the rafters you put one batten under the felt and then pull felt tight as you put another batten on directly on top of the tight felt on top of the under batten--this kicks the first row of tiles up to acomadate for overlap, on slates i think you just nail as the rest on top of felt

If you have made a mistake you will know when you get to the ridge board as the battens will be out and also your tiles and slates wont fit

 

[browfish]

Hi thanks for all that. YOu have sparked a few further questions now though.
What is the purpose of the second layer of felt?
SHould ever batton have a second batton on top, or is it just that bottom one?
What timber should i be using for the battons?

thanks

 

[Freddie]

Hi thanks for all that. YOu have sparked a few further questions now though.
What is the purpose of the second layer of felt? YOUR FELT IS ONLY 1 METER WIDE YOUR ROOF WILL BE A LOT HIGHER THAN THAT YOU LAY THE FELT ACROSS THE RAFTERS SIDE TO SIDE
SHould ever batton have a second batton on top, or is it just that bottom one?NO JUST THE VERY FIRST ONE IF YOU ARE USING TILES THIS IS TO ACCOMADATE THE MISSING ROW OF TILES THERE TO KICK YOUR TILE UP AT THE CORRECT ANGLE
What timber should i be using for the battons? 2"X1.5"


I would suggest you get someone who knows what they are doing to give you a hand mate

thanks

 

[browfish]

ah thanks again.
Sorry didnt realise you mean the second row of felt. I thought you meant cover the roof in felt, fix the battons, then cover the whole roof in felt again and repeat with more battons. I get ya now.
Any idea how far the tiles should overlap the edge?
thanks

 

[Freddie]

Depends what size guttering you are using, preferably the tile/slate should come no more than the middle of the guttering.

Dont forget to divide your roof into the amount of tiles/slates to get the correct and even coverage, wherever possible you want maximum coverage.

felting and battening a roof is a 2 man job and tiling/slating should be aswell in case of accidents

 

[browfish]

What about a 1 man, 1 woman job? I'll get the wife up there with me

The rafters overlap the outside wall by about 12" so i guess the gutter should be hunger under this. If this is the case, any idea how far the tiles should overlap the edge of the rafters to do this?

oh yeah, should i be using moisture permeable felt? The intention was to plasterboard under the rafters and insulate between.

Im not far of knowing where to start then.

thanks again

 

[Freddie]

What about a 1 man, 1 woman job? I'll get the wife up there with me

The rafters overlap the outside wall by about 12" so i guess the gutter should be hunger under this. If this is the case, any idea how far the tiles should overlap the edge of the rafters to do this?

oh yeah, should i be using moisture permeable felt? The intention was to plasterboard under the rafters and insulate between.

Im not far of knowing where to start then.

thanks again

I'll tell you what if i tell you how to do the roof me and your wife will watch from inside just in case you have an accident, if you give us a shout when you have finished we will bring the ladder back out.

At a guess i should say the end of the rafter top plus 2.25" for 4" guttering and to allow for the facia, and the end of the rafter top plus 2.74" for 5" guttering.

It would be better to give me your email so i can draw what i mean than doing it like this---oh yeah and dont forget your phone Number and what hours you work so i can give your wife her instructions on roofing aswell

 

[browfish]

You're a star. Is there a way of private messaging you my email address on here? THats if you reall dont mind doing a sketch. I feel really dumb but i guess you have got to learn the basics somewhere. I had to research everything to get me up to roof level and it worked, only thing i havent done soe far is laying the bricks (and i did those below the DPC)

 

[Freddie]

just put it on here NOW for a few minutes i will take it then delete-

 

[browfish]

edit

 

[Freddie]

ok got it delete it now

 

[Freddie]

ok browfish i am jen###### so ignore any others and i told you when i would send details---so no one winds you up

 

[browfish]

What sort of felt should i be putting on? I want to order that this week, along with the battons so i can get on.
thanks